• 한국유체기계학회 논문집
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• 제12권2호
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• pp.31-38
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• 2009

The valve performance has been evaluated from the theoretical equation based on design information such as packing thrust, spring preload and friction coefficient(${\mu}$). The accuracy of those data can be lower than that of vendor's initial design data. Especially, the friction coefficient can be degraded with time than the original condition and the valve performance calculated using the previous friction coefficient can not be available. Accordingly, this paper is describing a new performance evaluation method of valve based on diagnostic test data which are acquired from a site valve tested in static and dynamic conditions. Especially, this paper provides a new method using friction coefficient(${\mu}$) which is derived from the diagnostic test data acquired in the valve's design basis condition.

• 한국군사과학기술학회지
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• 제14권6호
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• pp.1138-1143
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• 2011

One of the critical items in radar testing is the ability to evaluate the performance of radar systems under real operational environments. But it takes lots of time and cost to operate real targets and analyze the test results due to a large amount of data based on these complicated environments. In this paper, the Radar Simulative T&E Lab. is introduced, and the test and analysis results of the developing radar for predicting the radar system performance are described in the Radar Simulative T&E Lab. This laboratory could be used to test the far-field characteristics of antenna radiation pattern and to perform an effective radar system test and evaluation using a simulative target generator under a low cost repeating test situation.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.686-691
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• 2007

The ride comfort is more important according to train speedup. Generally it is defined as the vehicle vibration. There are many studies on evaluation method of ride comfort for railway. In the case of Korean high speed train(HSR 350x), the ride comfort has been assessed by statistical method according to UIC 513R. To verify the design requirements for the performance of HSR 350x, the qualification tests had been conducted from August 19, 2002 to December 2004 and the stabilization and reliability tests are carried out nowadays. Up to December 2006, total test runs and the accumulated milage of the train were 357 times and 164,000km, respectively. A total of 352 ride indices had been acquired through the on-line test from Aug. 2002 to Dec. 2006. In this paper, we have reviewed the characteristics of ride comfort for HSR 350x according to the operational conditions, such as load and track conditions, season and used time, by using the tests data.

• Journal of Information Technology Applications and Management
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• 제11권4호
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• pp.209-225
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• 2004

This paper presents case studies on database Quality uSing an extended database Quality model developed by Korea Database Promotion Center, which shall be called KDPC2003. The model is applied to evaluate two kinds of databases ; one is an operational database, the other is an information service database. The purpose of this research is two-folded. One is to evaluate database quality and assess current status of database quality management; the other is to assess usefulness of KDPC2003 and to propose ideas for its augmentation. The findings in this study will provide basic facts to test database quality evaluation models.

• 한국경영과학회지
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• 제39권3호
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• pp.51-61
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• 2014

In this paper, we deal with developing a cost estimation relationships (CER) for Korean maneuverable weapons systems using historical production cost. To develop the CER, we collected the historical data of the production cost of four tanks and five armored vehicles. We also analyzed the Required Operational Capability (ROC) of the weapons systems and chose cost drivers that can compare operational capabilities of the weapons systems We used Forward selection, Backward selection, Stepwise Regression and $R^2$ selection as the cost drivers which have the greatest influence with the dependent variables. And we used Principle Component Regression, Robust Regression and Weighted Regression to deal with multicollinearity and outlier among the data to develop a more appropriate CER. As a result, we were able to develop a production cost CER for Korean maneuverable weapons systems that have the lowest cost errors. Thus, this research is meaningful in terms of developing a CER based on Korean original cost data without foreign data and these methods will contribute to developing a Korean cost analysis program in the future.

• 한국군사과학기술학회지
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• 제24권3호
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• pp.293-301
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• 2021

LTV(Light Tactical Vehicle) operating in our military requires higher levels of performance and durability to withstand harsher conditions than general vehicles, as they must travel on both rough-train and off-road as well as on public roads. Recently, LTV development is demanded a variety of test evaluations in order to satisfy ROC (Required Operational Capability) by the military requirement. However, there is no informations of driving test course for satisfying the durability performance of Korean tactical vehicle. Therefore, this study aims to provide basic data to establish reliable drive test conditions by analyzing the main maneuvering test site at the domestic and foreign country in order to select the representative drive course. These studies will provide a more scientific and systematic evaluation solution for the development of tactical vehicles, and can be effectively used to establish a certified system for military vehicle test evaluation in the future

• Steel and Composite Structures
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• 제27권3호
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• pp.327-335
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• 2018

This paper presents structural assessment of a steel railway bridge for current condition using modal parameter to upgrade finite element modeling in order to gather accurate result. An adequate monitoring, such as acceleration, displacement, strain monitoring, is important tool to understand behavior and to assess structural performance of the structure under surround vibration by means of the dynamic analysis. Evaluation of conditions of an existing steel railway bridge consist of 4 decks, three of them are 14 m, one of them is 9.7 m, was performed with a numerical analysis and a series of dynamic tests. Numerical analysis was performed implementing finite element model of the bridge using SAP2000 software. Dynamic tests were performed by collecting acceleration data caused by surrounding vibrations and dynamic analysis is performed by Operational Modal Analysis (OMA) using collected acceleration data. The acceleration response of the steel bridge is assumed to be governing response quantity for structural assessment and provide valuable information about the current statute of the structure. Modal identification determined based on response of the structure play significant role for upgrading finite element model of the structure and helping structural evaluation. Numerical and experimental dynamic properties are compared and finite element model of the bridge is updated by changing of material properties to reduce the differences between the results. In this paper, an existing steel railway bridge with four spans is evaluated by finite element model improved using operational modal analysis. Structural analysis performed for the bridge both for original and calibrated models, and results are compared. It is demonstrated that differences in natural frequencies are reduced between 0.2% to 5% by calibrating finite element modeling and stiffness properties.

• 한국시뮬레이션학회논문지
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• 제28권4호
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• pp.33-43
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• 2019

Link-16은 미 해군 및 공군, NATO에 합동 상호운용성을 제공하는 데이터링크로 국내 무기체계에서도 운용되고 있다. 현재 Link-16 운용을 위한 시험환경, 전술모의훈련 및 상호운용성 검증 시험은 해외 SW 및 도구를 통해 전적으로 의존하고 있다. 따라서 Link-16 기반의 운용환경시험 도구의 개발이 필요하다. 본 논문에서는 Link-16 해외도구 기능 분석을 통해 Link-16 네트워크 운용성능분석 시뮬레이터를 개발하였다. 또한 연동을 위한 SIMPLE 표준 인터페이스를 구현하였다. Link-16 네트워크 운용성능분석을 위한 기능모델은 사전분석, 실시간 운용분석, 사후분석 기능모델로 구성된다. 각 기능모델에 대한 시험은 해외 SW 및 도구와 SIMPLE 연동을 통해서 수행하였다. Link-16 네트워크 운용성능분석 시뮬레이터를 통해 해외 SW를 대체하게 된다면 우리 군에 맞는 전술훈련 및 네트워크 운용성능분석, 운용(시나리오)검증을 수행할 수 있을 것이다.

• 한국신뢰성학회지:신뢰성응용연구
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• 제17권2호
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• pp.150-158
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• 2017

Purpose: The RAM objective is a very important factor that has a great effect on the improvement of the operation ration during the operation maintenance and the reduction of the life cycle cost. It is used as a design criterion during the system development, and its sufficiency should be evaluated during its test evaluation. Method: This study analyzed the cases related to RAM objective setting and suggested the improvement measures. Result: The base data for RAM objective is OMS/MP, which needs to be drawn up under the supervision of the requirement military, and a high-accuracy operating availability should be set through ALDT calculation which reflects the military logistics support environment. In addition, data collection necessary for RAM objective and RAM analysis should be made by supplementing the input data of DELIIS. Conclusion: This study suggests improvement of RAM objective considering for the weapon system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2641-2643
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• 1999

This paper describes the first field demonstration of the distribution STATCON in Korea including installation and its evaluation for improving power quality in distribution system. The purpose of installation is to verify functionally the voltage source inverter based equipment for voltage regulation and harmonic mitigation in distribution line. The operational data resulting from field test and the site figure are included.